Measurement conversion

what does one jme-unit represent in centimeters?

good question!

Well, because I don't know I just use the blender measurement system and say that one blender unit is one unit for me. But maybe that's a bit to dirty…

You define that yourself. It's all relative  ;)

Just make sure to be consistent.

The general rule is 1 unit = 1 meter.  You can also use the com.jme.scene.measure package to do conversions that will be consistent with each other on the basis that 1 unit=1 meter

thanks for the replies… specially sbook… so 1 meter = 1 jme unit… with that in mind, I could also use alric's advice of defining my own measurements and just be consistent in my measurements… with that, I could derive that  1jme-unit could also be 1cm as long as I keep it consistent in my whole application… (and I personally think that 1m for 1jme-unit is to small…LOL)… thanks guys…Long live JME!!!

mhelz0001 said:

thanks for the replies... specially sbook... so 1 meter = 1 jme unit.... with that in mind, I could also use alric's advice of defining my own measurements and just be consistent in my measurements... with that, I could derive that  1jme-unit could also be 1cm as long as I keep it consistent in my whole application... (and I personally think that 1m for 1jme-unit is to small...LOL).. thanks guys...Long live JME!!!


Whatever you choose, be sure to pick your numbers carefully.  When you start getting into millions of units, the precision of floats becomes an issue and you start to see jittering effects.  This can effect anything from shadows to simply moving about the scene.  The effects of this are even more noticeable if you use much trigonometry in your application (Pi really screws things up  :x)

I'd like to add another question within this topic… In JMEPhysics, when we use setMass()… are we talking about grams here?

mhelz0001 said:

I'd like to add another question within this topic... In JMEPhysics, when we use setMass()... are we talking about grams here?


I'm not sure if Irrisor had specified any sort of definition for mass scale when writing the framework, but in looking over the ODE website I was unable to find any allusion to what the default unit was.

You might try asking on their mailing list here

they answered alright… but I still didn’t get what I needed…



http://groups.google.com/group/ode-users/browse_thread/thread/b22832e4af46fe5f



anyway, I remember in my highschool physics, that the measure of gravity is 9.8m/s^2 here on earth… how do I get JME’s implementation of gravity? is there a function to determine this significant variable?

In bullet 1unit=1meter and 1weight=1kg, you can set the gravity as a vector

is jbullet the same with jmephysics2? I'm starting out with JMEPhysics2 with irrisor's tutorials… am I going the right way or should I go with jbullet implementation?

Well, theres a thread about this and you can see some arguments in the thread in my signature, first page.